Technical Abstract: Geranium (Pelargonium x hortorum) is considered to be one of the
top-selling floriculture plants, and is highly responsive to increased macro- and micronutrient bioavailability. In spite of its economic importance, there are few nutrient disorder symptoms reported for this species. The lack of nutritional information for geranium during growth and development contributes to sub-optimal geranium quality. Understanding the bioenergetic construction costs during nutrient deficiency can provide insight into the significance of the element predisposing plants to other stress. Therefore, this study was conducted to investigate the impact of nutrient deficiency on plant growth. Pelargonium plants were grown hydroponically in a glass greenhouse. The treatment consisted of a complete modified Hoagland s mM concentrations of macronutrients (15 NO3-N, 1.0 PO4-P, 6.0 K, 5.0 Ca, 2.0 Mg, and 2.0 SO4-S) and µM concentrations of micronutrients (72 Fe, 9.0 Mn, 1.5 Cu, 1.5 Zn, 45.0 B, and 0.1 Mo) and 10 additional solutions each devoid of one essential nutrient (N, P, Ca, Mg, S, Fe, Mn, Cu, Zn, or B). The plants were photographed and divided into young, maturing, and old leaves, the respective petioles, young and old stems, flowers, buds, and roots at hidden hunger , incipient, mid and advanced stages of nutrient stress. Unique visual deficiency symptoms of interveinal red pigmentation was noted on the matured leaves of P and Mg deficient plants while N deficient plant developed chlorotic leaf margins Tissue N concentration greatly influenced bioenergetic construction costs, probably due to differences in protein content. This information will provide an additional tool in producing premium geranium plants for the greenhouse industry.